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The UK defended its decision to delay second-dose vaccines as the best way to fight the coronavirus, as more countries follow a similar strategy in a race against increasing cases and new strains.
UK Health Minister Matt Hancock said on Sunday that there is high confidence that the first dose will provide “decent efficacy” against the virus and that the country’s plan will speed up vaccinations across the country.
“You want as many people as possible to have protection as soon as possible,” Hancock said in an interview on Sky News. “This is the fastest way to save the most lives.”
Governments around the world are scramble vaccination programs as research shows that strains from the UK, South Africa and Brazil are more contagious or possibly even more deadly than the original virus. And countries are tightening restrictions on international travel as scientists assess whether the existing vaccines are equally effective against the variants.
Delivery problems also hinder the introduction of vaccines, increasing the pressure to give the first injections to as many people as possible, instead of holding back the doses to complete the two-course system earlier. Both AstraZeneca Plc. and Pfizer Inc. said they can’t meet delivery targets to Europe in the coming weeks, adding pressure to expand existing stocks. States in the US have also had to slow down their vaccinations due to difficulties in getting doses.
France on Saturday advised doubling the time between the first and second injection to six weeks, and concluded that this would lead to at least 700,000 additional people getting vaccinated in the first month.
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The shift to longer dosing intervals could double the number of people who receive some short-term protection against the virus, but carries risks. It is unclear how much benefit a single injection of currently available vaccines will provide, and there is a danger that mutations may flourish if immunity wanes after an initial dose.
French guidance
The new French advice is for the vaccine made by Pfizer and BioNTech SE, as well as another one supplied by Moderna Inc. Pfizer recommends that people get their second dose within three weeks, while Moderna recommends getting a second dose within four weeks.
France’s move came after January 21 statement from the U.S. Centers for Disease Control and Prevention that follow-up doses of Covid-19 vaccines can be given until six weeks later if it is not feasible to get them within the recommended interval. Also the US Food and Drug Administration offered some flexibility for ‘modest delays’.
Research from Israel, which is the world leader in vaccinations, shows that two days after a second injection, new infections and hospital admissions were both about 60% lower than their peak. However, in an encouraging sign for the step to delay the second dose, the trends started to shift about two weeks after the first shot.
The UK has already extended the maximum withdrawal period from three weeks to 12 weeks, as Boris Johnson’s government plans to vaccinate 15 million people by mid-February. The UK is also vaccinating with the shot developed by AstraZeneca, and it was most effective when administered with a gap of until 12 weeks.
The UK has already administered more than 6 million doses, most in Europe, and Johnson tweeted Saturday that every shot brings the UK closer to beating the virus. Just over 1 million people have been vaccinated in France.
Delays in dosing regimens are facing new questions from doctors, with the British Medical Association calling on the UK to “urgently review” its decision, allowing for the delay of the second dose of the Pfizer-BioNTech vaccine.
The BMA said in a statement that it delays until 42 days, or six weeks, citing international guidelines from the World Health Organization that this might work, but warned that the UK plan “goes much further than that.”
WHO guidelines
“BMA members are also concerned that given the unpredictability of supplies, there may be no guarantees that second doses of the Pfizer vaccine will be available in 12 weeks,” the group said in a statement.
The WHO has said there is no data to support the UK’s move, but has said changes in dosing regimens in emergencies may be warranted.
In its recommendation, the US CDC said, according to the guidelines, there is “limited efficacy data” of the Pfizer and Moderna vaccines beyond the six-week interval, but if the second dose is given later, “it is not necessary. to restart the series. “
(Updates with Israel study in 10th paragraph)